The present invention relates generally to a method and means for providing sterile/aseptic transfer of fluids between two containers. More particularly, the present invention relates to the formation of a sterile/aseptic connection between two containers.
As described in U.S. Pat. No. 4,022,256, the problem of the sterile transfer of fluid arises in a number of different areas. One area in particular includes the area of blood handling. Since blood contains several major different components, each serving a unique function, the use of whole blood for transfusion has become unnecessary in many cases. Instead, required components can be removed, allowing the balance of the blood to be employed elsewhere. Thus, blood component therapy has helped to ease the blood storage shortage somewhat, at a time of rapidly increasing demand.
In U.S. Pat. No. 4,022,256, the disclosure of which is incorporated herein by reference, there is described an arrangement wherein two sterile containers, one of which has a fluid which is desired to transfer to the other, are each formed of a plastic tube, or have a tube coupled thereto as an extension from the interior of the respective containers. Each tube has near a closed end or somewhere along its length, a "sterile transfer region" comprising a plastic material ("Material One") which can be made to melt and flow at a sterilizing temperature. These sterile transfer regions which can have any desired closed cross-sectional area, also contain a liner or window of a second material ("Material Two") on an inside thereof. Material Two will not melt at the temperature at which Material One melts and flows.
The containers are positioned so that their sterile transfer regions, overlap and are pressed against one another in a manner so that where they are in contact, there is an interface region of the meltable material, Material One, while the inside liners, constructed from Material Two, internally cover the walls opposite the location where the walls of the two sterile transfer regions touch. The region where the two sterile transfer regions touch is clamped together between two opposing jaws of a conduction heating device wherein one jaw may be a flat surface.
The disclosed connection system requires the use of exotic and relatively costly materials such as fluorinated ethylene propylene copolymer as the liner material. Moreover, the particular means used for melting the layers constructed from Material One can be cumbersome and ill-suited for some materials.
Another connection system is disclosed in U.S. Pat. No. 4,157,723. In this patent, there is disclosed a connection which may be formed between two sealed conduits in which each conduit carries an opaque, thermoplastic wall portion preferably having a melting range above essentially 200.degree. C. Preferably, the opaque thermoplastic wall portions are carried on the conduit about their periphery by transparent wall portions of the conduit. The opaque wall portions of the conduits are brought together into facing contact, and then exposed to sufficient radiant energy to cause the opaque wall portions to fuse together, and to open an aperture through the fused wall portions. This provides a sealed communication between the interiors of the conduits. The patent states that alternatively RF energy can be utilized.
In U.S. Pat. No. 4,325,417, there is disclosed another connector member for sealed conduits utilizing a crystalline plastic barrier membrane. In this patent, there is disclosed a connector member for a fluid flow path which comprises a transparent housing enclosing an opaque barrier membrane or wall portion blocking flow through the flow path. The barrier membrane is adapted to be openable by exposure to radiant energy from the interior through the transparent housing. In accordance with the disclosure, the barrier membrane is made of a predominantly crystalline plastic material, and accordingly, exhibits a relatively sharp melting point for improved opening characteristics upon exposure to the radiant energy.
In U.S. Pat. No. 4,434,822, there is disclosed a system for the sterile mixing of materials. In this patent, there is disclosed a fluid transfer assembly including first and second connector members, each associated with a fluid conduit and having a meltable wall which normally seals the connector member, and thus the associated conduit. The connector members can be coupled together with the meltable walls positioned in facing contact. One of the meltable walls includes a radiant energy absorbing material. The other meltable wall is relatively non-absorbent radiant energy, but does conduct heat energy. By exposing the coupled assembly to a source of radiant energy, the one wall melts in response to thermal radiation, while the other wall conducts heat energy from the melting wall to also melt. By melting, the walls open a fluid path between the fluid conduits.
Yet another sterile connector is disclosed in U.S. Pat. No. 4,253,500. In this patent, there is disclosed a sterile connector adapted for multiple junctions wherein a sealed, sterile connection may be provided between a pair or more of containers having transparent, flexible, thermoplastic sealed walls, each of which contains an opaque, relatively rigid, hollow sealing member in the general shape of a truncated cone, open at both ends. The containers are brought together in facing contact, and the hollow sealing members are nested together with portions of the transparent walls of the containers positioned therebetween. The nested, sealing member cones are irradiated with infrared energy through the transparent container walls to heat the nested sealing members. As a result of this, heat is conducted to the portions of the transparent walls between the nested sealing members to seal the portions of the transparent walls together in an annular area between the sealing members. A portion of the transparent walls retained in the nested sealing members may be torn away to make a sterile connection between the two containers.